This invention relates to providing a backflow prevention system for improved protection of municipal water distribution systems. More particularly this invention relates to providing a fire hydrant backflow prevention system.
Usually when firefighters need to supply a fire truck with extra water to fight a fire they connect a supply fire hose from the fire truck to a fire hydrant. However, it is sometimes necessary for fire fighters to obtain water from other water sources. It is not uncommon for firemen to draw water from swimming pools, mucky ponds, irrigation canals, and other unsanitary sources, especially in rural areas. Fire trucks may also draw water from fire hydrants connected to “brown water” and “gray water” reclaimed/non-potable water distribution systems (such as, for example, reclaimed water distribution systems used to irrigate golf courses, etc.). The same fire truck may then later connect to a fire hydrant of a potable water distribution system. Although water pressure from such a potable water distribution usually keeps contamination from entering the potable water distribution system, sometimes backflow conditions can occur which can result in contaminated water entering the potable water distribution system from the supply fire hose and fire truck water tank.
Further, fire fighters often add foaming agents and other chemicals to the water in the fire truck to assist in fighting fires. These chemicals can also contaminate potable water systems if backflow conditions occur when a fire truck is connected to a fire hydrant of a potable water distribution system.
Typically fire engine tanks are not disinfected before being attached to potable water distribution systems. If contaminated water backflows from a fire hose into a potable water system people drinking water from the system could suffer adverse effects from the health hazard of the contaminated water.
Even further, fire fighters aren't the only ones that draw water from fire hydrants potentially contaminating potable water distribution systems via backflow at fire hydrants. Others draw water from fire hydrants for a variety of uses (such as, for example, construction). Most municipalities usually require that commercial users drawing water from fire hydrants use a portable backflow prevention device; however not everyone complies with these requirements. In fact, it is not uncommon for people to illegally connect to fire hydrants to steal water from the potable water distribution system, and these people are unlikely to use a backflow prevention device. Such users drawing water from fire hydrants run the risk of introducing contaminants to the potable water distribution system.